hwmon: (smsc47m1) Simplify device registration

Use platform_device_register_full() instead of open coding this
function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/ab326fb9b1ad2191583b4cb3a8bd624dfedb908e.1701957841.git.u.kleine-koenig@pengutronix.de


[groeck: Removed double empty line]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>